The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 2002
Filed:
Jan. 07, 1999
Mitsunori Ueda, Chiba, JP;
Takeshi Kubo, Kanagawa, JP;
Junichi Suzuki, Kanagawa, JP;
Satoshi Sakamoto, Tokyo, JP;
Hiroshi Kawamura, Tokyo, JP;
Satoshi Hineno, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
An optical head used for recording/reproducing information signals for an optical disc having a light transmitting layer on a recording layer includes an actuator for the collimator lens. A collimator lens arranged between a light source and an objective lens is moved by the actuator for the collimator lens in a direction of cancelling the spherical aberration ascribable to thickness errors in the light transmitting layer. By this structure, the amount of generation of spherical aberration is reduced even if the numerical aperture NA of the objective lens loaded on the optical head is increased to render it possible to increase the recording capacity of the optical disc.